Computer Science 3 Marks Each

Makes web more interactive through online social media video sharing possible in the websites

4G gives a speed of approximately 100 Mbps whereas 3G gives a speed of approximately 2 Mbps. 4G takes less time than 3G in call establishment

Protocol: HTTP OR TCP/IP

Browser: Chrome OR Internet Explorer OR Firefox O R OPERA O R SAFARI OR any other correct Browser Name

PAN Examples:

(a) Connecting two cell phones to transfer data

(b) Connecting smartphone to a smart watch

LAN Examples:

(a) Connecting computers in a school

(b) Layout of computers in an office

FTP is a protocol to transfer files over the Internet, whereas HTTP is a protocol which allows the use of HTML to browse web pages in the World Wide Web.

Spam is the abuse of electronic messaging systems (including most broadcast media, digital delivery systems) to send unsolicited bulk messages indiscriminately.

Speed–

• Faster web browsing

• Faster file transfer

Service –

• Better video clarity

• Better security

FTP OR Telnet OR TCP

A Trojan Horse is a code hidden in a program, that looks safe but has hidden side effects typically causing loss or theft of data, and possible system harm.

Packet Switching follows store and forward principle for fixed packets. Fixes an upper limit for packet size. Message Switching follows store and  forward principle for complete message. No limit on block size.

Packet Switching follows store and forward principle for fixed packets. Fixes an upper limit for packet size. Message Switching follows store and forward principle for complete message. No limit on block size.

When a Website with cookie capabilities is visited, its server sends certain information about the browser, which is stored in the hard drive as a text file. It’s a way for the server to remember things about the visited sites.

A worm is a self-replicating computer program. It uses a network to send copies of itself to other computers on the network and it may do so without any user intervention.

Most of the common anti-virus(anti-worm) remove worm.

(a) Wired – Optical Fiber

(b) Wireless – Infrared OR Microwave

(b) and (c)

Bus topology

StarTopology

Advantages:

(i) It is easy to install and maintain.

(ii) It is very inexpensive.

(iii) It can be easily connected.

Disadvantages:

(i) Because of high attenuation, it is incapable of carrying a signal over long distances without the use of repeaters.

(ii) Its low bandwidth capabilities make it unsuitable for broadband.

Server facilitates sharing of data ,software and hardware resources (e.g. printers , modems etc.) on the network.

Two threats to network security are:

(a) Snooping : Unauthorized access of someone else’s data , email etc

(b) Eavesdropping : Secretly listening someone else’s private communication.

Firewall (both in hardware form or software form) prevents unauthorized access to or from a private network.

A modem is a networking device that allows a computer to connect and communicate with other computers via telephone lines. Modem translates digital signals of a computer into analog signals of a computer (modulation) so that they can travel via telephone lines and again converts received analog data into digital data (demodulation).

LAN - Small computers networks that are confined to localised area are known as Local Area Networs (LAN).

For example office, building , school.

WAN - On the other hand, network spread across countries are known as Wide Area Network. It is a group of servers that are separated by large distances and tied together. For example Internet.

Resource sharing . For example , a printer can be shared among 20 stand alone computers.

Reliability : A file can have copies on two or more different machines. So if one computer is down or unavailable, other copy can be used.